


A Bushel of Blueberries

by Vexatious



Series: Twin Papyrus AU [2]
Category: Undertale (Video Game)
Genre: Alternate Universe - Underswap, Cum Inflation, Cum Swallowing, Dirty Talk, Dom Sans, Domberry, Double Penetration, Ecto-Genitalia (Undertale), Ecto-Penis (Undertale), Ecto-Tongue (Undertale), Ecto-Vagina (Undertale), Explicit Language, Explicit Sexual Content, Facials, M/M, Multiple Orgasms, Oral Sex, Overstimulation, Sexual Exhaustion, Skeleton Sex (Undertale), Sub Papyrus, Swapcest - Freeform, Threesome, Twin Papyrus Au, Underswap Papyrus, Underswap Sans, lewdberry
Language: English
Status: Completed
Published: 2017-12-25
Updated: 2017-12-25
Packaged: 2019-02-20 09:54:30
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,389
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13144200
Author URL: https://archiveofourown.org/users/Vexatious/pseuds/Vexatious
Summary: Underswap Sans meets his twins in Snowdin Forest and decides to take them home to meet his brother. The more the merrier, right?





	A Bushel of Blueberries

**Author's Note:**

> Requested by mellednsfw on Tumblr.  
> Check out my Tumblr: [vex-bittys](http://vex-bittys.tumblr.com)

With Blue gone on another one of his Human Patrols, Stretch finally had the chance to enjoy some alone time in the peace and quiet of their Snowdin home. He lit a cigarette and reclined on the couch in that slouchy way that always made his proper little brother’s socket twitch. Blue hated smoking in the house too, but Stretch would just open some windows before he came back that night. The lanky skeleton sighed happily, taking a drag of his cig and a swig from his honey bottle. He was definitely living the dream…

… until a small blue boot nearly kicked down the front door to a chorus of excited chatter.

“PAPY LOOK WHAT I FOUND!” his very Magnificent brother shouted excitedly.

“better not be an actual human,” Stretch grumbled under his breath, quickly snuffing out his cigarette between his phalanges and cramming it into the couch cushions to hide it. Blue giggled, and the sound echoed strangely as Stretch finally dragged his tall frame into an upright position.

Someone must’ve spiked his honey because there in the doorway stood his adorable little brother, mweh heh heh’ing proudly with his hands on his hips, flanked by two exact copies of himself. Only Blue would leave on a mission to capture humans and find himself… literally. If Stretch wasn’t a skeleton made of magic, his jaw bone would’ve been lying on the floor.

“what… how… ?” At a loss for words, Stretch just gestured at the three small, battle body-clad skeletons with a perplexed expression written across his face.

“I FOUND THEM IN SNOWDIN FOREST!” Blue explained, beaming excitedly. “THEY CAME FROM A UNIVERSE JUST LIKE OURS, BUT THEY’RE TWINS!” He held out his arms as if he’d just revealed a grand prize on an NTT game show. Stretch couldn’t argue with that analogy; the other two versions of his brother were watching him coyly with faint blue blushes spreading across their round cheekbones. Suddenly, Stretch craved blueberries.

“I’M BB, AND THIS IS BERRY!” one twin declared, bouncing forward to stand shoulder-to-shoulder with the original Blue.

“YOUR BROTHER IS HOT,” the other twin stage-whispered to Blue, who giggled.

“HE LOOKS EXACTLY LIKE YOUR BROTHER!” Blue pointed out as Stretch stepped forward to examine these replicas of his beloved baby bro. As he inspected them, they wiggled excitedly, and soon all three of the small skeletons dissolved into flirtatious laughter.

Stretch did occasionally sleep with Blue, but only when the need for physical affection fully consumed the would-be Royal Guard. Most of the time, his little brother kept busy and free from “lewd behavior” by patrolling, training, and practicing his still-lacking cooking skills. Any time Blue succumbed to his desire was nice, and from the way all three sets of big cerulean eyelights regarded him with open lust, this latest development was going to be thrice as nice. Time to unleash some clever pick-up lines!

”geez, bro, i’m seeing double… triple even! maybe we should go upstairs to my room so that i can lie down, and we can all get acquainted,” he winked cheekily at the three now-glaring Sanses.

”HIS PUNS ARE EVEN WORSE THAN OUR BROTHER’S!” BB groaned.

“DON’T SAY THAT!” Blue interjected. “IF YOU SAY HIS PUNS ARE BAD, HE JUST MAKES WORSE ONES!”

“alas, i have been slandered,” Stretch fake-gasped, pressing the back of his hand to his skull and collapsing dramatically into his brother’s arms. Blue held him up easily, though from the look on his face, Stretch was one terrible pun away from being dropped on the floor. The silent threat didn’t stop him. “you three will have to take me upstairs and  _pun_ -ish me.”

“SEE? HE’S INCORRIGIBLE!” Blue huffed, exasperated, but instead of dropping his snarky brother, he pushed the taller skeleton back into an upright position.

“THEN LET’S PUNISH HIM!” Berry shouted gleefully.

“TO THE BEDROOM!” Blue pointed the way unnecessarily, feeding off of the twins’ excitement. He tossed Stretch casually over his shoulder and bounded up the stairs with him, followed by his pair of eager doubles.

Stretch couldn’t believe his good fortune as he planned out a night of indulgent depravity in his mind. His mouth, hands, and cock would be busy for hours if these two new Sanses, BB and Berry, shared his brother’s excessive energy. Maybe, once he got tired, they’d start pleasuring each other and let him watch. Maybe they’d let him take pictures or make a video for later. Fantasies chased each other through his imagination, each more lascivious than the last, and by the time Blue placed him on the bed, Stretch could barely wait to get his clothes off and get started.

BB and Berry shed their outfits in a matter of seconds, gloves, boots, and pants flying to all corners of the room. They watched Stretch with hungry, half-lidded eyes as if he were a Gyftmas present waiting to be unwrapped. Stretch never rushed though. He never rushed for personal tasks, and he certainly never hurried when it came to undressing his handsome little brother. Nothing warmed Stretch’s magic like ghosting his hands over Blue’s smooth round bones, and he refused a skip a step just because they had company.

Stretch unbuckled Blue’s battle body and set it reverently on the floor. The homemade armor meant so much to Blue that Stretch always handled it with the utmost care. As he lifted Blue’s shirt, he traced the curve of each rib, making his brother shudder in anticipation of the pleasure to come. The twins observed the ritual, starry-eyed at the almost hypnotic movements of Stretch’s hands. The tall skeleton slid his hands into his brother’s gloves, pushing them off of the much smaller set of hands within before entwining their fingers. Blue tilted his head upwards for a kiss, and Stretch, as always, obliged, pressing their mouths together before slowing opening his to display his bright orange tongue.

Blue immediately opened his mouth, inviting his brother’s tongue inside with a hushed moan as the saliva-slicked orange appendage dominated the smaller pale blue one. Humming, Blue suckled at Stretch’s tongue, pulling it further into his mouth as he stroked it with his own. He hated to admit it, but he loved the sweet acrid flavor of honey and tobacco from his brother’s kisses. Their tongues danced and writhed together while Stretch gently positioned Blue onto his back. Lifting his brother’s hips, Stretch slipped the smaller skeleton’s pants off, taking the boots with them, his palms riding the peaks of Blue’s iliac crests down to the valley of each pubis. Blue’s magic coalesced quickly under Stretch’s expert touches.

Focused on the task at hand, Stretch nearly forgot about the audience until one of them spoke.

“NO, NO, NO! BLUE, WE’RE SUPPOSED TO BE PUNISHING PAPY. YOU CAN’T PUNISH HIM WITH A… A… THAT!” Berry protested, puffing out his cheeks indignantly.

“IF YOU WANT TO SEDUCE PAPY PROPERLY, YOU NEED TO MAKE… THE OTHER ONE!” instructed BB, pointing to the obvious bulge in Stretch’s khaki shorts to clarify his words.

“I’VE NEVER DONE IT THAT WAY BEFORE, BUT THE MAGNIFICENT SANS NEVER BACKS DOWN FROM A CHALLENGE!” Blue’s tiny fists were balled up in profuse excitement.

“NEVER FEAR! WE, THE MAGNIFICENT SANSES, SHALL DEMONSTRATE!”

Stretch struggled to hold in his chuckles. These three diminutive skeletons who didn’t even dare to whisper naughty words like “pussy” and “cock” were openly planning to dominate him. How adorable. Stretch wholeheartedly approved of their efforts. Anything that involved less work on his end was worth trying at least once. Plus, he couldn’t resist one determined Blue, much less three of them.

“go for it, little bros,” he offered, stretching out on the bed, still clothed, so that they could have their way with him unimpeded. He did not expect to be dragged off of the bed and onto the floor by strong, enthusiastic hands that made quick work of undressing him. They had him splayed out before he could even process their assertive handling of him, and when his thoughts finally caught up to the situation he saw the twins staring down at his massive, twitching erection in consternation. Blue still sat on the bed, taking everything in as it unfolded.

“NO!” said BB, wagging a finger at the summoned magic as if it were a naughty pet. “DISMISS YOUR MAGIC, PAPY!” With a smile, Stretch complied, folding his arms behind his head for comfort. If they wanted to start with a clean slate, he wouldn’t object. Their delight at his obedience made it worth it.

“OUR PAPYRUS IS VERY LAZY, SO WE DO THIS PART FOR HIM!” explained Berry. Blue nodded, all too familiar with his own brother’s lethargic ways, and the twins both leaned in over Stretch’s pelvis, faces lit by the orange glow of arousal emanating from the lovely bones beneath them.

Two baby blue tongues extended languorously and began to lap at Stretch’s pubic symphysis. Stretch gasped at the sensation of their warm, wet tongues sliding against his heated bones. The twins curled their magical appendages alluringly around the cartilage, sucking and nipping at the surrounding bone. They mewled happily when Stretch’s orange magic settled low in his pelvis, forming a delectable little mound with luxurious puffy lips, already slick with arousal. The twin Sanses hummed with pride at the fruit of their labor.

“OH, PAPY, IT’S PERFECT!” breathed Blue, hopping off of the bed to get a closer look at his brother’s freshly summoned pussy- a sight he’d never witnessed before! BB and Berry spread Stretch’s lips wide, putting his glistening slit and tiny hole on display. Blue plopped down, straddling Stretch’s waist to peer at his two doubles as they began to prepare his brother for sex.

The twins bowed their heads and each of them swiped his tongue up Stretch’s slit. “HE TASTES SO SWEET!” moaned Berry, diving in for another taste.

“YOU HAVE TO TRY THIS, BLUE!” instructed BB. Soon the three Sanses huddled together, skulls touching, as they lapped at Stretch’s sweet juices. Three fat little tongues took turns darting into the tall skeleton’s narrow opening, curling and squirming against his sensitive walls as his back arched and he began to moan in earnest under their combined attentions. Blue copied a strategy that his brother used on him and brushed his thumb over the swollen little clit that Stretch had formed; Stretch cried out, bucking his hips reflexively. A wicked grin spread across Blue’s face. He had discovered Papy’s weakness.

BB and Berry added their fingers to the ministrations of their tongues, taking care to slowly stretch this new Papy’s pussy. They pumped their small fingers in and out of the tight hole while Blue focused on his brother’s clit. Blue circled the sensitive nub with his tongue before trying a gentle nip. Stretch’s hips bucked again- success! Humming and purring his brother’s name to vibrate his tongue against the bundle of nerves and magic, Blue started to slurp and suck at it. Without warning, Stretch’s entire body jolted, causing his pussy to seize up as he came, squirting fluids onto the twins’ startled faces.

“OH, PAPY, YOU’RE SO RESPONSIVE!” Blue squeezed his legs together to keep his magic from forming into a pussy a second time. His lookalikes were gently licking the mess off of each other’s faces.

“you could let me return the favor, Blue,” murmured Stretch reaching up to caress his brother’s femurs. The offer tempted Blue, but he wanted to try something new while the other two Sanses were available to teach him. He pushed Stretch’s hands back down to the floor. The lanky skeleton pouted.

“MMM, I THINK HE’S READY NOW!” giggled BB, grabbing Stretch by the shoulders and turning him so that his hands supported him. Berry grabbed Stretch’s hips and repeated the motion so that the tall skeleton propped himself up on his hands and knees in the middle of the room.

“THIS POSITION WILL WORK PERFECTLY!” declared Berry. Berry and BB each stroked their own pubic symphysis briefly, concentrating until they’d summoned two identical shafts, just slightly smaller than Stretch’s usual length and girth. Blue gazed at the faintly glowing blue erections, starry-eyed. He still hadn’t managed to conjure anything, so he motioned for the twins to start without him.

“WE’LL MAKE YOU FEEL REALLY GOOD, PAPY!” promised Berry, petting one of Stretch’s cheeks as he rubbed his member against the other. BB aligned Stretch’s hips and began wetting his shaft by grinding it against the tall skeleton’s entrance.

Stretch’s mouth opened seemingly of it own accord to accept the offered cock, and Berry gasped under his breath as the underside of his length slid across Stretch’s tongue and into his throat. BB buried his own length to the hilt in Stretch’s hot, tight pussy with almost no resistance. Once he’d entered the luxurious warmth, BB felt Stretch’s walls clench as if to draw him in further, as if his very flesh begged for more.

“HE’S TAKING ME SO DEEPLY!”

“HE’S SQUEEZING ME SO TIGHTLY!”

Blue grinned, elated that his brother could impress these two worldly Sanses. He was learning so many new techniques! His eyelights locked on BB as the small skeleton began to pound into Stretch, hands grasping his hipbones for leverage. Each powerful thrust sent Stretch’s body rocking forward and Berry’s cock sliding deeper down the magic passage of his throat. Berry lovingly stroked the submissive skeleton’s skull as his own hips bucked with the rhythm of his twin’s.

Stretch’s tongue poked out of his mouth and drool dribbled down his chin as he swallowed around the thickness filling his mouth. BB’s sizable shaft stuffed his hole thoroughly, and every time the small skeleton withdrew, only to ram back in even deeper than before, Stretch thought he might burst. The tall skeleton relished that feeling of too much then not enough, and his eyelights rolled back in his head as pressure built in his core.

Berry groaned, nearing completion already due to the expert clenching and tugging of Stretch’s swallowing motions. His phalanges scraped Stretch’s skull as he fought to hold out. BB released one of Stretch’s hips to run his small hand up and down the lanky skeleton’s spine, the firm grip and the up and down movement adding an addition layer of pleasure to Stretch being fucked at both ends. The twins closed the distance between them and clacked their teeth together in a skeleton kiss, opening their mouths and entwining their tongues to the music of their breathy moans. Blue’s magic itched to coalesce, and he set to work forming it into the correct tool for the task ahead. The twins were close; Blue could tell. Then it would be his turn.

With a muted screech, Berry came, clutching Stretch’s skull as he forced his cock down the tall skeleton’s throat. Cum spurted down Stretch’s throat in thick ropes, and he swallowed, gulping down every bit. The sensation of hot magic sliding down his throat pushed Stretch over the precipice into his own orgasm. His cunt spasmed, locking around BB’s shaft and driving him over the edge as well. Bright blue seed spilled into Stretch’s translucent orange magic with each throb of BB’s cock, and he stayed buried in the sucking warmth even after he’d spent his entire load.

“MY TURN!” Blue had crafted a noteworthy member, and he was ready to use it. Berry moved aside, presenting Stretch’s now-empty mouth to this universe’s singular Magnificent Sans. Stretch’s body trembled as BB pulled out, and the twins panted slightly with exertion. After a hushed discussion, Berry offered to take Stretch’s pussy next while his twin recovered for the next round. Stretch’s face flushed a vibrant shade of orange at the sight of his brother’s manifested magic. Blue looked good enough to eat.

Uninhibited lust clouded Blue’s eyelights as precum began to leak from the tip of his cock. “OH, PAPY. I WANT YOU SO BADLY. MWEH. I’M GOING TO FACE-FUCK YOU, PAPY. WITH MY… C-COCK.”

Emboldened by Blue’s lewd words, Berry blurted: “AND I’M GOING TO WRECK YOUR PRETTY… YOUR CUNT!”

The unexpected dirty talk seared Stretch’s magic with unbridled desire. He opened his mouth wide, and Blue plunged into him, bracing his hands on his brother’s skull as he crammed his cock all the way down his throat. Berry wasted no time slamming into Stretch from behind, pushing him forward so roughly that he gagged. Blue and Berry set a furious pace, and Stretch could barely do more than hold his position as they used his body for their pleasure.

The vibrations of Stretch’s moans, the squeezing sensation as his brother swallowed around his cock, and the sloppy massaging of his tongue on the underside of his shaft quickly drove Blue to the edge of orgasm, but he stubbornly refused to cum so early. Berry moaned loudly as Stretch’s pussy convulsed in another orgasm, but he didn’t slow his thrusts. Instead, he began to fondle Stretch’s floating ribs, something he knew his own brother enjoyed immensely. Stretch nearly screamed, overwhelmed by the sudden sensation on his sensitive bones, and Blue took the opportunity to release his load down his brother’s yawning throat.

“SWALLOW IT ALL PAPY!” Blue cried as Stretch’s tongue continued to assault his cock, dragging every last drop of Blue’s magic into his waiting mouth. Fuck, his little brother’s cum tasted so good.

Berry’s pace stuttered, and he dug his fingertips into Stretch’s hips as he reached his own orgasm. Forcing his length in as far as he could, he emptied his hot load into Stretch, causing a third orgasm as the lanky skeleton’s overstimulated pussy drank down the fresh offering. Stretch’s entire body spasmed with the force of his orgasm. Satiated, he began to lower himself to the floor to rest, only to find BB’s small hand lifting his chin.

“OH, NO, PAPY, WE’RE NOT FINISHED YET.”

* * *

The three Magnificent Sanses kept up their efficient rotation and soon Blue found himself positioned at his brother’s mouth again. Body shaking with fatigue, Stretch could barely support his lanky frame, much less move, but Blue and the twins supported him as they continued to fuck him mercilessly. As Blue neared yet another orgasm, he decided to try something different. Pulling out at the last minute, he sprayed thick strands of his cum onto his brother’s face. Beautiful!

Stretch’s bones were alight with endless pleasure and aching from the endless stimulation. Pure bliss fogged his mind as yet another orgasm ripped through his body. It hurt as his battered pussy vibrated and clenched the invading cock for the umpteenth time, and Stretch wondered if he was going to faint. The influx of so much cum had forced his ecto-body to form, stomach distended with a swirl of luminous blue semen. When Berry finally pulled out, he delicately rubbed Stretch’s bulging stomach, and cum gushed from the tall skeleton’s battered, gaping cunt.

Blue kissed his brother’s cheekbone, nuzzling their faces together affectionately, not caring about the cum that now coated both of their cheeks. He marveled at this new way of displaying his love for his brother, but poor Papy appeared to be completely spent. They would have to let him recuperate before they tried anything else.

“YOUR BROTHER DIDN’T LAST NEARLY AS LONG AS OURS!” observed BB while Blue picked up his brother’s limp body and carried him to his bed. Normally he abhorred a mess and would’ve insisted Papy bathe, but his brother needed to recover more than he needed to be clean at the moment.

“I THOUGHT YOU CAME HERE BECAUSE YOUR BROTHER WAS WORN OUT FROM SEX?” Blue asked, confused.

“THAT’S BECAUSE HE HADN’T SLEPT IN THREE DAYS!” BB replied with an impish grin. Berry tucked Stretch into bed, and Blue kissed his forehead, lapping up a stray strand of cum that had settled on his brother’s brow.

“HIS STAMINA WILL IMPROVE IF YOU PRACTICE, AND WE’LL ASSIST YOU!” offered Berry.

“DO YOU HEAR THAT, PAPY? WE CAN DO THIS AGAIN TOMORROW… AND THE NEXT DAY… AND THE DAY AFTER THAT!” Blue babbled excitedly.

Stretch didn’t know whether to be turned on or terrified as he slipped into a deep healing sleep in preparation for more sex sessions to come with three faux-innocent round faces quietly chuckling as his lullaby.

“MWEH HEH HEH!”


End file.
